diff --git a/raster3d/r3.in.v5d/binio.c b/raster3d/r3.in.v5d/binio.c
index f8582e97313..b04dceeef0f 100644
--- a/raster3d/r3.in.v5d/binio.c
+++ b/raster3d/r3.in.v5d/binio.c
@@ -147,7 +147,7 @@ static void if_to_c(long *t, const long *f)
 {
     if (*f != 0) {
         *t = (((*f & 0x8000000000000000) |
-               ((*f & 0x7f80000000000000) >> 7) + (16258 << 48)) |
+               ((*f & 0x7f80000000000000) >> 7) + (16258L << 48)) |
               (((*f & 0x007fffff00000000) >> 8) | (0x0000800000000000)));
         if ((*f << 1) == 0)
             *t = 0;
@@ -160,7 +160,7 @@ static void if_to_c(long *t, const long *f)
 #define IF_TO_C(T, F)                                                   \
     if (F != 0) {                                                       \
         T = (((F & 0x8000000000000000) |                                \
-              ((F & 0x7f80000000000000) >> 7) + (16258 << 48)) |        \
+              ((F & 0x7f80000000000000) >> 7) + (16258L << 48)) |        \
              (((F & 0x007fffff00000000) >> 8) | (0x0000800000000000))); \
         if ((F << 1) == 0)                                              \
             T = 0;                                                      \